Question

In the reaction $2NaOH+H_{3}P{O}_4\to N{a}_{2}HP{O}_4+2H_{2}O$, the Equivalent weight of the acid is

• A. $49$
• B. $98$
• C. $32.6$
• D. $36.5$

Answer 1

Answer: (A)

$49$

Here, the acid is phosphoric acid.

It's molar mass is $98g/mol$.

Equivalent weight of acids are calculated by dividing the molar mass of the acids with number of hydrogen ions donated by acids.

Here Phosphoric acid has donated $2H^{+}$ ions.

Therefore,

Equivalent weight$=\frac{98g/mol}{2}=49g/mol$

Hence, this is the answer.